Abstract

Introduction

The goals of this study were (i) to compare the prevalence of focal knee abnormalities,
the mean cartilage T2 relaxation time, and the spatial distribution of cartilage magnetic resonance (MR)
T2 relaxation times between subjects with and without risk factors for Osteoarthritis
(OA), (ii) to determine the relationship between MR cartilage T2 parameters, age and cartilage morphology as determined with whole-organ magnetic resonance
imaging scores (WORMS) and (iii) to assess the reproducibility of WORMS scoring and
T2 relaxation time measurements including the mean and grey level co-occurrence matrix
(GLCM) texture parameters.

Methods

Subjects with risk factors for OA (n = 92) and healthy controls (n = 53) were randomly
selected from the Osteoarthritis Initiative (OAI) incidence and control cohorts, respectively.
The specific inclusion criteria for this study were (1) age range 45-55 years, (2)
body mass index (BMI) of 19-27 kg/m2, (3) Western Ontario and McMaster University (WOMAC) pain score of zero and (4) Kellgren
Lawrence (KL) score of zero at baseline. 3.0 Tesla MR images of the right knee were
analyzed using morphological gradings of cartilage, bone marrow and menisci (WORMS)
as well as compartment specific cartilage T2 mean and heterogeneity. Regression models adjusted for age, gender, and BMI were used
to determine the difference in cartilage parameters between groups.

Results

While there was no significant difference in the prevalence of knee abnormalities
(cartilage lesions, bone marrow lesions, meniscus lesions) between controls and subjects
at risk for OA, T2 parameters (mean T2, GLCM contrast, and GLCM variance) were significantly elevated in those at risk for
OA. Additionally, a positive significant association between cartilage WORMS score
and cartilage T2 parameters was evident.

Conclusions

Overall, this study demonstrated that subjects at risk for OA have both higher and
more heterogeneous cartilage T2 values than controls, and that T2 parameters are associated with morphologic degeneration.